﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.ServiceProcess;
using System.Text;
using System.Threading;

namespace GPSTK103ProtocolListenerWindowsService
{
    // State object for reading client data asynchronously
    public class StateObject
    {
        // Client socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 512;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
    }

    public partial class GPSTK103ProtocolListenerWindowsService : ServiceBase
    {        
        public const int BufferSize = 512;


        // Thread signal.
        public static ManualResetEvent allDone = new ManualResetEvent(false);

        // Enum Field
        enum MessageField
        {
            Imei = 0,
            Event = 1,
            DataTime = 2,
            Unknow1 = 3,
            Unknow2 = 4,
            Unknow3 = 5,
            Unknow4 = 6,
            Latitude = 7,
            Unknow5 = 8,
            Longitude = 9,
            Unknow6 = 10,
            Speed = 11
        }


        public GPSTK103ProtocolListenerWindowsService()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            try
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("--- GPS Tracking Server Start Listening TK103 V1 ---", "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("IP: " + System.Net.Dns.GetHostName(), "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Port: " + Properties.Settings.Default.Port.ToString(), "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Max Connections: " + Properties.Settings.Default.MaxConnections.ToString(), "TK103");

                Thread TCPListenerThread = new Thread(StartListening);
                TCPListenerThread.Start();
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("TK103 Server is DOWN", "TK103");
            }
        }

        protected override void OnStop()
        {
            GPSTrackingDBCustom.Log.WindowsServiceLog.Warning("--- GPS Tracking Server TK103 Is DOWN ---", "TK103");
        }

        public static void StartListening()
        {
            IPEndPoint ep = new IPEndPoint(IPAddress.Any, Properties.Settings.Default.Port);

            // Create a TCP/IP socket for listner.
            Socket listenerSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            // Bind the socket to the endpoint and wait for listen for incoming connections.
            try
            {
                listenerSock.Bind(ep);
                listenerSock.Listen(Properties.Settings.Default.MaxConnections);

                while (true)
                {
                    try
                    {
                        // Set the event to nonsignaled state.
                        allDone.Reset();

                        // Start an asynchronous socket to listen for connections.
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Waiting for a connection TK103.....", "TK103");
                        listenerSock.BeginAccept(new AsyncCallback(AcceptCallback), listenerSock);

                        // Wait until a connection is made before continuing.
                        allDone.WaitOne();
                    }
                    catch (Exception ex)
                    {
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error Waiting for a connection..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, "TK103");
                        listenerSock.Shutdown(SocketShutdown.Both);
                        listenerSock.Close();
                    }

                }

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("TK103 Server is DOWN", string.Empty);
            }
        }

        public static void AcceptCallback(IAsyncResult ar)
        {
            try
            {
                // Signal the main thread to continue.
                allDone.Set();

                // Get the socket that handles the client request.
                Socket listener = (Socket)ar.AsyncState;
                Socket handler = listener.EndAccept(ar);

                // Create the state object.
                StateObject MessageDevice = new StateObject();
                MessageDevice.workSocket = handler;
                handler.BeginReceive(MessageDevice.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), MessageDevice);
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("TK103 Server is DOWN", string.Empty);
            }
        }

        public static void ReadCallback(IAsyncResult ar)
        {
            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject MessageDevice = (StateObject)ar.AsyncState;
            Socket handler = MessageDevice.workSocket;

            // Read data from the client socket.
            int bytesRead = handler.EndReceive(ar);

            try
            {
                //No Message 
                if (bytesRead <= 0)
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device. No Message", "TK103");
                    handler.Shutdown(SocketShutdown.Both);
                    handler.Close();

                    return;
                }

                //Process Message Hande Held
                string Message = System.Text.UTF8Encoding.UTF8.GetString(MessageDevice.buffer).Replace("\0", "");


                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Message Device: " + Message, "TK103");
                string[] MessageArray = Message.Split(new char[] { ',' });

                if (MessageArray.Length == 3)
                {
                    //Send command OK
                    string MessageSend = "**," + MessageArray[(int)MessageField.Imei + 1] + ",B";

                    System.Text.ASCIIEncoding Encoding = new ASCIIEncoding();
                    SendCommand(handler, Encoding.GetBytes("LOAD"),1); 
                    SendCommand(handler, Encoding.GetBytes(MessageSend),2);

                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Message Device: " + Message + "GPS Replay Location", "TK103");
                    // Not all data received. Get more.
                    handler.BeginReceive(MessageDevice.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), MessageDevice);
                    return;
                }



                string DeviceID = MessageArray[(int)MessageField.Imei].Replace("imei:", "");                
                string DeviceLatitude = MessageArray[(int)MessageField.Latitude];
                string DeviceLongitude = MessageArray[(int)MessageField.Longitude];
                string DeviceSpeed = MessageArray[(int)MessageField.Speed];

                double Speed = Convert.ToDouble(DeviceSpeed) * 1.852; //Converto knots to KM   1KM = 1.852

                //Convert NMEA
                //Convert Lat.
                int LatDegree = Convert.ToInt32(DeviceLatitude.Substring(0, 2));
                double LatMinute = Convert.ToDouble(DeviceLatitude.Substring(2));

                LatMinute = LatDegree + (LatMinute / 60);

                //Convert Long.
                int LongDegree = Convert.ToInt32(DeviceLongitude.Substring(0, 3));
                double LongMinute = Convert.ToDouble(DeviceLongitude.Substring(3));

                LongMinute = LongDegree + (LongMinute / 60);
                LongMinute = LongMinute * -1;

                //Insert to Database
                GPSTrackingDBV2.Entities.TrackData TrackDataEntity = new GPSTrackingDBV2.Entities.TrackData();
                try
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Inserting track message to database ...", "TK103");
                    GPSTrackingDBV2.Entities.TrackDataLastLocation TrackDataLastLocationEntity = new GPSTrackingDBV2.Entities.TrackDataLastLocation();

                    TrackDataLastLocationEntity.GpsImei = TrackDataEntity.GpsImei = DeviceID;
                    TrackDataLastLocationEntity.DateTime = TrackDataEntity.DateTime = DateTime.Now;
                    TrackDataLastLocationEntity.Latitude = TrackDataEntity.Latitude = LatMinute;
                    TrackDataLastLocationEntity.Longitude = TrackDataEntity.Longitude = LongMinute;
                    TrackDataLastLocationEntity.Heading = 0;
                    TrackDataLastLocationEntity.Speed = Speed;

                    GPSTrackingDBV2.Data.DataRepository.TrackDataProvider.Insert(TrackDataEntity);

                    //Update last location  
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Updating last track message location to database ...", "TK103");
                    try
                    {
                        GPSTrackingDBV2Custom.Data.DataRepository.TrackDataLastLocationProvider.UpdateOrInsert(TrackDataLastLocationEntity);
                    }
                    catch (Exception ex)
                    {
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error Updating last track message:" + ex.Message, "TK103");
                        // Disconnect Hand Held                            
                        Send(handler, Encoding.ASCII.GetBytes("Error Updating>" + ex.Message));
                    }


                }
                catch (Exception ex)
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error Inserting track message:" + ex.Message, "TK103");
                    // Disconnect Hand Held                            
                    Send(handler, Encoding.ASCII.GetBytes("Error Inserting>" + ex.Message));
                }

                // Disconnect Hand Held                      
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device.", "TK103");
                //Send(handler, Encoding.ASCII.GetBytes("OK"));

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error message invalid:" + ex.Message, "TK103");
                // Disconnect Hand Held                    
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();

                //Send(handler, Encoding.ASCII.GetBytes("Message Invalid"));
            }

        }

        private static void Send(Socket handler, byte[] MessageSend)
        {
            try
            {
                // Begin sending the data to the remote device.               
                handler.BeginSend(MessageSend, 0, MessageSend.Length, 0, new AsyncCallback(SendCallback), handler);
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, "TK103");
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("TK103 Server is DOWN", string.Empty);
            }
        }

        private static void SendCallback(IAsyncResult ar)
        {
            // Retrieve the socket from the state object.
            Socket handler = (Socket)ar.AsyncState;
            try
            {
                // Complete sending the data to the remote device.
                //int bytesSent = handler.EndSend(ar);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device.", "TK103");
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error SendCallBack..... " + ex.Message, "TK103");
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
            }
        }

        private static void SendCommand(Socket handler, byte[] MessageSend, int LineNumber)
        {
            // Begin sending the data to the remote device.
            GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Command Send: " + System.Text.UTF8Encoding.UTF8.GetString(MessageSend).Replace("\0", ""), "TK103");
            handler.BeginSend(MessageSend, 0, MessageSend.Length, 0, new AsyncCallback(SendCallbackCommand), handler);
        }

        private static void SendCallbackCommand(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = handler.EndSend(ar);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Command... Send " + bytesSent.ToString() + " bytes to gps device.", "TK103");

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error Command..... " + ex.Message, "TK103");
            }
        }
    }
}
